Part 3:What went wrong?

Read carefully through the following four problems (Questions 11-14).Each problem includes a mistake of some kind, and we would like you to explain what is wrong.

1. Over the years, Dr. Gundlach has observed that student scores on her midterm and final exams have a strong, positive, and linear relationship.She would therefore like to construct a regression equation in order to predict final exam score based on midterm exam score.As a first step, Dr. Gundlach creates a scatterplot, with final exam score on the x-axis (or horizontal axis) and midterm exam score on the y-axis (or vertical axis).

1. If the correlation between two variables is positive, this means that if we want to predict one variable based on the other, the intercept in the regression equation must also be positive.

1. Upon gathering data from a random sample of classmates, Margaret reports the correlation between favorite color and major to be r = 0.63.

4.When asked if the correlation of r = 0.25 is weaker than the correlation of r = -0.75, Philip says "no."